


The Mission

by sirenalley



Category: Naruto
Genre: Consensual, Dirty Talk, Established Relationship, Fear of Discovery, Female Uchiha Itachi, M/M, No Uchiha Massacre, Oiroke no Jutsu | Sexy no Jutsu, Oral Sex, Sibling Incest, Vaginal Fingering, Vaginal Sex
Language: English
Status: Completed
Published: 2020-12-28
Updated: 2020-12-28
Packaged: 2021-03-11 04:49:14
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,605
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28389552
Author URL: https://archiveofourown.org/users/sirenalley/pseuds/sirenalley
Summary: “Oiroke no jutsu allows for a more practical, hands-on application,” Itachi added, and this time his eyes met Sasuke’s across their plates, black and fathomless in that perfectly unfamiliar stranger’s face he still recognized like he’d grown up next to it. “Thank you for understanding.”A week wasn’t long. He could hold it together.
Relationships: Uchiha Itachi & Uchiha Sasuke, Uchiha Itachi/Uchiha Sasuke
Comments: 10
Kudos: 65





	The Mission

**Author's Note:**

> My most uninspired fic title yet. 
> 
> Happy Holidays!

A week out from his older brother’s anticipated two-month mission leave in Tea Country, Itachi arrived for dinner in the body of a woman. Oiroke no jutsu had its own tells—aside from plain physical resemblance, the chakra activation proved weak to an Uchiha’s visual prowess. It was elementary. He knew as soon as Itachi entered the room that, not only was the woman his brother, this illusion was in fact a deliberate use of jutsu. 

He stared rudely, uncomprehending. 

“There you are,” Fugaku said at the table as though nothing was amiss. “I thought you might be late tonight, but I was hoping it wouldn’t interfere with your mother’s efforts. She has the whole week of meals planned.”

“Thank you for waiting.” Even Itachi’s voice carried the evidence of change, lifted by an octave, losing depth and tenor where it gained rounded, feminine syllables. Still it reeked of familiarity—every word precise and polite. “The mission debrief extended later than anticipated.”

“No, that’s all right. I expected as much.”

Sasuke could not move past the titanic state of his own shock. He watched his brother slide neatly to his knees in his place at the table. He wondered at the absurdity of this nightmare coming to pass, fueled out of pathetic longing he could associate only with his older sibling and reformed into the surreal event of a family dinner. He catalogued every miniscule difference: Itachi’s shoulders were slighter in breadth, waist trim, facial features sloped as though the jutsu had wiped away all sharp angles with one gentle brushstroke. Everything else was disguised by the androgynous uniform he wore. Sasuke also noticed, because he looked long and hard enough, that his brother’s eyelashes were still dark and thick and his hair fell in the same silky sheet, bound back as usual.

Itachi was made entirely womanly by the technique, but what surprised Sasuke was that it didn’t look crude or exaggerated, not in any way that demonstrated his understanding of the jutsu.

Fugaku must have noticed his staring. While their mother unloaded plates and dishes of food onto the table, their father said, “Itachi will spend the next few days preparing for his upcoming ANBU mission.”

“As a woman?” 

Silence made the air brittle. Fugaku set down his chopsticks. “Oiroke no jutsu is a technique that is often abused. Although easily perceived as inflammatory, in this case—”

“Have you _seen_ Naruto use it? Or his sensei?”

“A technique in any hand is only as good as its user,” came his father’s high-minded reply. Sasuke thought it was bullshit. Jiraiya was an exceptional shinobi, but he was also a brazen pervert. His father knew that, Itachi knew that. 

As for Naruto, the jury was still out, but personally Sasuke didn’t have significant expectations for his future.

“Genjutsu would work just as well,” he argued. “Better. The target would never stand a chance against someone like Itachi.”

Itachi himself hadn’t acknowledged the conversation since taking his seat. He kept his eyes down, delicately organizing his plate with food as though decorating an art display rather than a meal intended for consumption. When he spoke, his voice was another jolting surprise of feminine words. 

“The goal is to create a widespread, physical manipulation of the environment rather than focus on a single target. Oiroke no jutsu does not require much chakra to maintain, which makes it suited for long-term assignments. Additionally, even if it is detected, it won’t raise substantial alarm with the enemy. Most likely, it’ll be dismissed outright and undermined. I’m afraid I cannot share any of the particulars beyond that.”

“That’s all right,” Fugaku said. “We understand.” 

The emphasis on _we_ made him scowl. Sasuke absolutely didn’t understand why his parents accepted the fact Itachi would be practicing _how to be a woman_ for an entire week before embarking on some unquestioned, ambiguous mission that required it. Was he seducing an entire village? Did the location forbid men? 

“Oiroke no jutsu allows for a more practical, hands-on application,” Itachi added, and this time his eyes met Sasuke’s across their plates, black and fathomless in that perfectly unfamiliar stranger’s face he still recognized like he’d grown up next to it. “Thank you for understanding.”

Something slickly hot slithered down into Sasuke’s belly, betraying him in a burn that reached the back of his neck as he dropped his head. A week wasn’t long. He could hold it together.

—

He could _not_ hold it together.

That righteous speech on the jutsu honed to craft in the hands of a talented shinobi, to master the illusion of an environment, to efficiently manage resources—Sasuke was convinced his brother hadn’t needed practice. 

Itachi’s movements were borne of inherent grace, and the care in his outward appearance and perception combined with the uncanny adaptability that underlined his genius meant such a simple assignment was almost an insult. But that was how many people treated Itachi. Perhaps because they couldn’t understand him, they underestimated his capacity to acclimate to any condition, even outlandish assignments like _oiroke no jutsu_.

Sasuke understood him better than anyone. 

Tomorrow, Itachi would leave on his mission beyond the village. Tonight, his black eyes had remained fastened to his little brother throughout dinner, flaying him like hot glass over an ant.

It was infuriating. Childishly worse than that: _unfair_.

The veranda outside was dark and shaded by eaves against the lit interior of the house, so at first he didn’t see Itachi. He knew he was here. He’d followed him out on an impulse, but it felt as though he had been doing that the past few days. _Following_. Like a deranged, lust-sick animal beholden to their own hindbrain nature. He monitored his brother through the act of pretending to be a woman, which honestly didn’t seem to be as great a deviation from his normal behavior as their father had made Sasuke believe. 

His brother’s figure was displaced in the shadow, so Sasuke was able to find him on a second look-around. He wanted to be seen. If he hadn’t, then Sasuke would be forced to fumble in the dark, seeking wispy breath in the cold mid-winter air as his only true clue.

Sasuke approached. “I didn’t know what to think at first, but I’m getting used to it.”

“Are you?” Itachi stood with his back to a beam supporting the roof. He leaned, arms crossed, in a plain black hanten wrapped tight across his midsection to disguise the body beneath. “You adjusted quickly.”

“I only had a week. You’ll be gone tomorrow.”

“That’s correct.”

Their gazes were level, a fact that did not escape his attention. He’d caught up in height these past few years, but it seemed the jutsu had narrowed the difference completely; it gave Sasuke an almost crawling discomfort. Nothing explicit or extreme. It was just strange, somehow worse than Itachi’s current temporary transformation. Every inch shaved off between them was a step further from childhood into adulthood. It was like the closer he got to Itachi, the more _real_ his older brother became, no longer the figment of idealization he’d constructed out of a younger sibling’s hero worship. 

“You don’t look that different,” Sasuke said to end the quiet. 

“Did you expect me to?”

His eyes rolled. “Yeah. Is that a real question? You’ve seen what it’s actually made to do, despite whatever you decided to use it for.”

“You say that as though this operation was my decision.”

“Am I wrong?”

His brother said nothing. Once, that deliberate pause would have made him squirm, but now Sasuke stared him down, waiting expectantly for the reply.

“There is a reason for that difference, as you describe it.”

“I can take a guess. You’re more conservative than the typical person who would use this technique, so that’s part of it. Based on that, I doubt your assignment is meant to be strictly for seduction. Otherwise…”

Itachi’s brow rose. “Otherwise?”

Sasuke’s eyes strayed to the ground. It wasn’t a product of embarrassment, although he could feel heat reach the tips of ears, but instead that he simply couldn’t look at his brother and outline the logic behind his argument. His mind lost its train of thought, never mind its ability to reason. Barreling on: “You would look more womanly.”

“I see. You mean I would possess more indecent features.” Itachi’s voice was low, and he didn’t think he imagined the _taunting_ he heard, nor the weight of his brother’s gaze. “Then your belief is that the seduction of a target requires certain physical changes in order to be successful. Larger breasts, perhaps? Revealing cleavage? Wider hips? On a simple-minded target stimulated by the visual alone, that could be true. However, if the target is more complex—”

“More intelligent.” Sasuke’s face was ablaze; he knew it now. 

Itachi smiled a dangerous curve in the dark. “In that case, you would be more successful influencing their environment, and their mind, rather than just their eyes. The mind is a powerful tool. If you want conviction, you should understand your opponent as well as they understand themselves.”

“But you’re not using genjutsu,” Sasuke said. “I don’t get it. You could do all of that easier and faster with the Sharingan. They’ll figure it out, this is too basic.”

“You figured it out as soon as I walked in the door.”

“So?”

“I suppose,” his brother’s voice came gently, arms unfolding, “that makes you a complex target.”

Sasuke took a step forward as though possessed, sealing the space between them like a letter. He couldn’t decide if he was complex or just insane as he helped Itachi lower his arms by pushing them aside and holding them down by the wrists, the thin bones warm in his closed palms. Their faces hung close together. Then he kissed Itachi—an act he’d done several times now, but never when his brother’s mouth was a woman’s mouth, altered against his lips. He tasted the stale, humid flavor of Itachi’s breath. He was surprised to find the actual differences minimal. While his brother yielded to the pushy caress of his tongue, deeper entry was as scalding wet as always, blunt teeth a barrier to the soft, melted interior. 

That didn’t mean there wouldn’t be more significant disparities elsewhere.

He moved one of his hands from Itachi’s wrist and hooked the hanten’s belt with a thumb to yank it open, then dove beneath, mapping out his brother’s chest. The swell of Itachi’s breasts was small; below modest clothing they wouldn’t be remarkable, but that suited him. A flagrant display of sexualty wasn’t like Itachi Uchiha. That one fit perfectly into the hard cup of his hand was better. He wasn’t wearing anything for support, so there was nothing to impede Sasuke’s hungry roving touches, groping across his chest until he could feel nipples stiffen into tiny little peaks.

“Sasuke,” his brother rasped in that silky, feminine voice when their lips slickly separated. “This isn’t an appropriate place.”

“I don’t care.”

“You should.” The way Itachi said this was a critique, which made it simpler to ignore than if it had been a demand. Itachi critiqued him at breakfast, lunch, and dinner; he commanded him far less often, and so its rarity reserved obedience.

Sasuke’s touch ventured further south.

The space between his brother’s legs was mercilessly hot. Of everything, this surprised Sasuke the most. Having never been with a woman, he didn’t know what to expect when his hand slipped beneath the elastic of his brother’s underwear—his _panties_ , a word he couldn’t yet associate with Itachi—and scraped through the dark curls waiting for him on his descent. He wasn’t prepared for the pure warmth there, fingertips feeling the seam that marked the most vulnerable part of his brother’s new body.

In the quiet dark, Itachi’s breath caught and held.

“You’re wet,” Sasuke said as he pried open that slit with his fingers, stroking through the slick evidence of arousal and gloating at its discovery. It was an identical victory-high every time he made his brother’s dick hard. Proof: _You’re turned on. I did this._ “Don’t tell me it’s just a ‘normal reaction to physical stimulation’, because I won’t believe you. You were waiting.”

“Lower your voice,” his brother scolded somewhere near his ear, voice stilting high over the last word as Sasuke slid a forefinger into his pussy. “We’re still—within range—”

“They don’t hear anything,” Sasuke soothed, eyes lidded at the unbelievably soft, gliding heat that locked tight over his knuckles. Impatience brimming like honey in an overfull cup, his middle finger soon wedged in beside the first, the sudden stretch causing Itachi to flatten his spine abruptly to the beam at his back. “I can cover your mouth if it’d make you feel more secure.”

The slanted, disapproving look on Itachi’s face didn’t last at the next twist of a wrist, prying him open. He’d pushed both waistbands low enough on Itachi’s hips to achieve a decent angle; his other hand pulled Itachi’s shirt up to expose his chest. 

The mouth-watering sight of Itachi’s bare tits, heaving with every ragged breath he took, did little to instill patience. Lust sunk through his belly and into his cock. His brother’s pale body gleamed in the black night surrounding them, skin around dusky nipples tight and pebbled with the cold. He wanted to suck on them. He didn’t wait or ask permission as his head lowered to fasten his mouth over one, dragging teeth across the taut peak so it was wet and shiny under his tongue, feeling Itachi’s rigid frame against his front. Sasuke kept fingering him while one palm groped his chest so the perfect handful of those tits would never be bereft as he traded attention back and forth—groping and sucking like an animal until he’d turned Itachi’s nipples rawly pink with diligence.

He realized he was grinding the sore neglect of his own dick against his brother’s thigh when Itachi levered him backward with an elbow. Sasuke’s messy fingers slid loose from where they were wedged all the way up Itachi’s cunt to the third knuckle. The air burned them, frigid compared to that hot internal temperature.

They looked at one another: Itachi panting, shirt shoved up around his collarbones and hanten hanging open, bare breasts and hips on lewd display in a way no one, _no one_ but him had ever seen—and Sasuke fully dressed, smirk bending wolfish as he popped his fingers into his mouth and licked off that thick, slippery flavor.

“You taste good,” he said. “I want to use my mouth on you.”

“You did.” How Itachi could sound composed while half-stripped and breathless would never make any sense. 

“That’s not what I mean.” A pointless argument when Itachi knew, but Sasuke said it anyway, prowling in again. “I want my mouth,” his hand rubbed the wet fabric at the crux of his brother’s thighs, “right here, I want to shove my tongue inside and taste you, until you’re a wreck, after I’ve made you come so hard you have to beg me to stop—”

The screen door clacked open. Itachi’s grip closed like iron over his arm, steering back as he adjusted to cover himself. They could not be seen at the shadowed corner facing the garden; still, their mother’s voice was close. “Itachi, Sasuke? What are you doing out here? It’s getting cold, you should come in.”

Sasuke rubbed the roof of his mouth with his tongue, that musky taste soon diluted by spit.

“I was discussing the mission with Sasuke,” his brother said, calm as anything, “and the date I expect to return.”

“He’ll be waiting at the door.” Sasuke could tell by tone their mother was smiling. “I hope you won’t be gone too long this time.”

“I won’t.” Itachi separated completely from him and turned around. He went quietly into the house, lights swallowing him in a halo of warm color, slight shoulders straight across. Sasuke’s gaze scorched after him. He thought that, if he looked hard enough, he might be able to uncover evidence of himself on Itachi, some signal that he’d just had two fingers scissoring into that tight, soaked slit—clenched thighs, wrinkled fabric, an unsteady gait—but there was nothing. Not a hair’s strand out of place. He had even refastened the hanten across his chest, everything beneath it hidden from view if not for hungry imagination.

So Sasuke followed, deliberately slower.

—

They fucked in Itachi’s room three hours later. It was further from their parents’ bedroom, so it was the habitual choice, although it had taken Sasuke months of whittling down his older brother’s natural inclination for caution to allow it. Even then it had to be the dark dead of night, silent except for their shared breath and the glide of skin on skin.

He had waited like he couldn’t make it another minute, frustration burned down to the wick by the time he had Itachi straddling his face on the mattress, so wet he lapped up that heady taste like a hot syrup, tonguing across a tender clit again and again. When Sasuke finally slid his dick inside, it was an unreal feeling, separate from their previous experiences but not dissimilar. A brand new intimacy. Itachi’s hair was long and cool and ticklish around their shoulders with every slick rejoining. The strength behind each deep, desperate thrust bruised their hips. Wringing an orgasm out of Itachi was, too, a vivid achievement that turned him human—expression cracked in pleasure, slack jawed, breath carrying voice. Sasuke came first while fully buried inside Itachi’s pussy; the second time, he came on Itachi’s tits in slick, glossy threads. 

Multiple rounds begged a lot of Itachi’s stamina. Even worse the night before a long mission. He might have felt guilty if not for how fucked-out Itachi looked lying on the sheets, hair a loose black cloud, eyelashes damp, the curves of a woman’s body bringing softness to the corners of his frame. Guilt could come later. His gaze devoured the sight of his brother in its impossible beauty like it would be snatched out of his hand in the next moment.

Sasuke knew the body didn’t matter. The allure between them wasn’t defined only by physical attraction—it was because of who they were. Magnetically bound, he understood that no one would ever be able to stand in the tower of his older brother’s presence, not to him. These indulgent allowances only demonstrated that truth. The bond between them would never break.

As moonlight cut in through the window, he held Itachi asleep to his chest, calmed by the soothing rhythm of his brother’s heart. He admired the peace that touched Itachi’s pretty face; shed, finally, of reservations and appearances.

Just a few more minutes. Then Sasuke would will himself back to his own bed.

—

Like a chastised, hand-shy dog, he followed Itachi to the perimeter of the Uchiha compound under a scudded blue sky. Itachi carried a single pack over one shoulder and led the way. When they reached the gate that marked the transition into Konoha’s greater streets, he stopped, and Sasuke pulled up short at his back.

Neither of them said a word for several seconds. He began an attempt to apologize when Itachi turned, interrupting. “You cooked my breakfast this morning.”

“Yeah.”

Itachi smiled, a touch of fatigue under the look. “It was good.”

“Mother already had the ingredients prepared. I didn’t do much.”

“The thought counted more to me.”

“Itachi,” he said. “About last night, I shouldn’t have gone overboard with… you know. It was inconsiderate given the parameters of your assignment and the travel you have to do today. ”

His brother wasn’t looking at him. His eyes had drifted as a group of shinobi passed, each dressed in the familiar ANBU uniform, animal masks fixed over their faces. They were likely Itachi’s teammates, headed toward the rendezvous location at the edge of the village where they would depart.

When he addressed Sasuke again, that small bemused smile hadn’t faded. “There’s no need to apologize.”

“Still—”

“Sasuke.” His brother lifted one pale, elegant hand and formed a quick seal. Then he transformed directly in front of Sasuke’s eyes—the illusion of feminine features melting into the sharp, handsome cut of Itachi’s profile. A return to normal. That same hand extended to flick him on the forehead. “Forgive me.”

He stared, stupefied, brow red where Itachi’s knuckle struck. He watched his brother begin to walk away.

“You—” Sasuke shut his mouth, opened it again, shut it. Gaping like a stupid fish. “You—there wasn’t really—you…” He felt warmth in his cheeks and down his neck. “You _tricked me_.”

“And Father,” Itachi said as he retreated, “though I’d prefer if you didn’t tell him. It would be difficult to explain. I’ll see you in two months, otouto.” 

Itachi’s expression was hidden from view, but it didn’t matter. He could tell that smile had become treacherous, slanting into the smirk he wore only when he knew it would be missed, when he could get away with it in an elaborate ruse.

There was no mission imperative for _oiroke no jutsu_. Itachi had just wanted to see what his horny little brother would do.

_Asshole_.

Sasuke scrubbed a hand over his face after he was alone, sighed, turned and kicked a rock. Then he went home. Two months charted out a tiny lifetime in his mind—plenty of weeks to dream up a scenario to get Itachi back for the sheer humiliation. 

He grinned into his palm.

**Author's Note:**

> You can find me on [twitter](https://twitter.com/unholyknives)! :)


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